Propulsion kit

ABSTRACT

The present invention is a propulsion kit that is attached to a gliding air to surface bomb. The kit of the invention comprises one or more engines and, when activated, allows a significant extension of the length of the flight path of the bomb. The engines can be any type of air-breathing engine for example jet engines. The kit can be designed to be retrofitted to an existing gliding bomb. The kit of the invention allows the original bomb to function in one of the three following modes, depending on the bomb size and the aerodynamic characteristics: the original operation mode, an improved gliding ratio mode, and a cruise trajectory mode.

FIELD OF THE INVENTION

The invention is in the field of armaments. Specifically, the invention is an add-on propulsion kit for the range extension of an air to surface bomb.

BACKGROUND OF THE INVENTION

Free-fall air to surface bombs have been used since the very beginnings of military applications of airborne systems. The main shortcoming of such bombs is that the airplane must approach relatively close to the target in order to release the bomb. The relatively short stand-off distance places the airplane and its crew at great risk from antiaircraft defensive weapons, especially ground to air missiles.

In order to overcome the problem of short stand-off distance, various types of free-gliding bombs and air to ground missiles powered by rocket motors or air breathing engines have been developed. Despite the development of missiles there is still an important place in the arsenal of modern air forces for gliding bombs, which in certain scenarios can have advantages, e.g. lower cost and higher payload.

Methods have evolved involving the attachment of aerodynamic lift and control surfaces, such as various shapes of wings, control fins, and tail structures to the bomb, in order to increase stand-off distance and also to allow control of the flight trajectory of the bomb after release from the launch vehicle. In most cases these surfaces are folded against the sides of the bomb during captive flight and are deployed when the bomb separates from the airplane that launches it. Typical prior art solutions are described in U.S. Pat. Nos. 5,141,175, 5,615,846, and U.S. Pat. No. 6,152,041.

It is a purpose of the present invention to provide a kit that can be attached to existing gliding air to surface bombs that will significantly extend their range.

Further purposes and advantages of this invention will appear as the description proceeds.

SUMMARY OF THE INVENTION

The present invention is a propulsion kit that can be attached to a gliding air to surface bomb. The kit comprises:

-   -   (a) a fuel tank;     -   (b) a mounting and operation interface section; and     -   (c) one or more engines;

When the engines are activated, a significant extension of the length of the flight path of the bomb is achieved.

The engines of the kit of the invention are air-breathing engines, preferably jet engines.

The propulsion kit of the invention can be designed to be able to be retrofitted to any existing gliding bomb. The principal components of the mounting and operation interface section are: a power supply unit; an engine control unit; and an electric cable, which provides a link between the mission computer of the bomb and the operation interface of the kit.

The use of the propulsion kit of the invention allows the original bomb to function in either an improved gliding ratio mode or a cruise trajectory mode.

All the above and other characteristics and advantages of the invention will be further understood through the following illustrative and non-limitative description of preferred embodiments thereof, with reference to the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing a gliding bomb and the principal components of the kit of the invention; and

FIG. 2 schematically shows the three modes of operation of the gliding air to surface bomb according to the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention is a propulsion kit that is attached to a gliding air to surface bomb. The kit of the invention is based on the use of one or more engines and, when activated, allows a significant extension of the length of the flight path of the bomb. The engines can be any type air-breathing engine for example jet engines. The kit can be designed to be retrofitted to an existing gliding bomb. The kit of the invention allows the original bomb to function in one of the three following modes, depending on the bomb size and the aerodynamic characteristics:

-   -   (a) original operation mode—the kit of the invention is not         attached;     -   (b) improved gliding ratio mode—the kit of the invention is         attached and activated but the thrust of the engine/s is less         than the drag of the bomb; and     -   (c) cruise trajectory mode—the kit of the invention is attached         and the thrust of the engine/s balances the drag of the bomb.

In FIG. 1 is schematically shown the main components of the kit of the invention. At the center of the figure is a conventional gliding air to surface bomb 10, shown attached to the fuselage 12 of an airplane (gliding wings folded) Above and below bomb 10 are shown the main components of the kit 20 of the invention. The kit is comprised of three main components. Fuel tank 22, mounting and operation interface section 24, and one or more engines 26 (two engines are shown in FIG. 1). Principal components (not shown in the figure) of mounting and operation interface section 24 are a power supply unit, an engine control unit, and an electric cable that provides the link between the mission computer of the bomb and the operation interface of the kit.

The kit 20 is attached to bomb 20 by means of the mounting interface in section 24. The mounting is done by conventional methods well known in the art and does not require any structural changes to bomb 20. If the kit is later removed, bomb 20 is returned to its original form and can be used as originally designed, i.e. in mode (a) above.

The activation of the kit is coordinated with the operation of the bomb and the kit's operation is implemented by the mission computer of the bomb to which additional flight control code relating to the properties and operation of the kit, e.g. number and type of engines present and required mode of operation, has been added. When activated by supplying voltage from the plane to the bomb, the mission computer checks, among other things, for the presence of a kit of the invention. If the presence of a kit is established, then the systems are operated according to the mission plan of the bomb, which takes into account the additional capability supplied by the kit. Either before release of the bomb or during the free flight period after release the starting routine will activate a series of activities in the engine control unit of the kit that will culminate in engine start and stabilization of the thrust provided by the engine, or engines if more than one is present, to operate the bomb in either mode (b) or mode (c).

FIG. 2 shows schematically a graph of altitude A vs. range R for each of the three modes of flight of the air to surface bomb. For the graph depicting mode (b), point x signifies the release of the bomb from the airplane and point y, the ignition of the engine of the kit. For the graph depicting mode (c), point z represents the location at which the bomb is released and simultaneously (or slightly before release) the engine is ignited. The distances in FIG. 2 are not meant to be anything other than schematic; but, as shown, the use of the kit of the invention has significantly extended the range of the bomb, i.e. has increased the stand-off distance and safety of the air crew. In practice in mode b (improved gliding ratio) the stand-off range may be doubled or more while in mode c (cruising mode) the increase in the stand-off range depends on the amount of fuel in the fuel tanks of the bomb.

Although embodiments of the invention have been described by way of illustration, it will be understood that the invention may be carried out with many variations, modifications, and adaptations, without exceeding the scope of the claims. 

1. A propulsion kit that can be attached to a gliding air to surface bomb, said kit comprising: (a) a fuel tank; (b) a mounting and operation interface section; and (c) one or more engines; wherein, when said one or more engines are activated, a significant extension of the length of the flight path of said bomb is achieved.
 2. A propulsion kit according to claim 1, wherein the engines are air-breathing engines.
 3. A propulsion kit according to claim 1, wherein the engines are jet engines.
 4. A propulsion kit according to claim 1, wherein said kit can be designed to be able to be retrofitted to any existing gliding bomb.
 5. A propulsion kit according to claim 1, wherein principal components of the mounting and operation interface section are: a power supply unit; an engine control unit; and an electric cable.
 6. A propulsion kit according to claim 5, wherein the electric cable provides a link between the mission computer of the bomb and the operation interface of said kit.
 7. A propulsion kit according to claim 1, wherein use of said kit allows the original bomb to function in one of the following two modes: (a) improved gliding ratio mode; and (b) cruise trajectory mode. 